Mental images and expectancies shape our perception of the world. Cognitive psychologists have determined such influences on sensory processing with psychophysical measures of phenomena such as mental rotation of objects, apparent motion, and perceptual restoration of speech sounds. They concluded that remembered representations of the world actively structure sensory processing. "Adaptive resonance" and "reentrant" theories propose that interactions of incoming sensory information and experientially derived expectations generate dynamic activity patterns within networks of reciprocal cortico-cortical, cortico-thalamic, and cortico-limbic connections. Unfortunately, very little is known about the actual neurophysiological mechanisms underlying the perceptual interface. In the proposed research, we will use dense-array electroencephalography (EEG) to dissociate sensory and cognitive components of auditory evoked potentials (AEPs). We will do so using a novel approach that measures potentials emitted in response to well-defined cognitive events that occur in the absence of sensory input. Our initial data indicate that imagining continuations of pitch sequences elicits emitted potentials, even when there is no expectation to hear a sound. In the first step, we will further establish conditions necessary for generating emitted potentials and compare emitted potentials elicited using our method with emitted potentials elicited using the traditional "oddball" paradigm. Next, we will compare and contrast elements of AEPs and emitted potentials in order to evaluate and extend current theories pertaining to the mechanisms by which attention and memory mediate interactions of expectancies/images with sensory input. Additionally, we hope our experiments will establish the use of simple musical materials as a tool for studying non-verbal auditory working memory and sequence learning. The proposed research will set the stage for an R01-scale project in which we seek to identify the neural generators and circuits involved in auditory mental image formation using functional magnetic resonance imaging (fMRI), intracranial EEG recordings, and constrained source localization modeling of EEG recorded at the scalp. If successful, our proposed line of research may produce many wide-ranging benefits. Subsequent research based on our results may ultimately lead to the diagnosis and treatment of learning disorders, an understanding of auditory hallucinations in schizophrenia, and the creation of neural prostheses that control external devices based on the specific mental images generated by the user.